The present invention relates to an apparatus for treating hydrocephaly, more specifically, for draining an intracerebral space in hydrocephalic patients. Such devices are capable of draining fluid from an intracerebral space by means of drainage conduits disposed subcutaneously and leading into a body cavity for the removal of fluid which has not been resorbed. Valve means are normally arranged in the drainage conduit.
Prior art drainage devices of the type described above are capable to remove fluid from a ventricular space when the fluid pressure in such space exceeds a predetermined valve pressure. Thus, such prior art devices are limited to preventing the continuous exceeding of a fluid pressure in the cerebral space which fluid pressure must be determined by separate measurements and by experience. This type of apparatus is further unable to prevent so-called hyper-drainage as a result of reduced pressure in the drainage conduit.
Furthermore, detailed investigations have shown that the fluid pressure in the ventricular space may differ in different patients and it may even differ in one and the same patient, depending on different circumstances, thus, the well being may be substantially disturbed in a patient who must use prior art drainage sytems in which the valve opening or response pressure is adjusted but once and thereafter cannot be changed again after implantation of the device.